Unmanned aerial vehicles (UAVs) are used by hobbyists, some commercial entities, and various militaries. Many UAVs include an integrated camera system to capture imagery of the UAV's environment. These captured images can be used for various purposes. As one example, the images can be used to allow the UAV to fly autonomously to a destination without a human operator controlling the UAV in any respect. For instance, the UAV can capture images of its environment during flight, and utilize the captured images for navigational purposes (e.g., determining its location, trajectory, etc.), safety determinations (e.g., object detection and avoidance), or to build up knowledge of the UAV's environment (e.g., building a three-dimensional (3D) model of the UAV's environment).
When it is raining or snowing in the UAV's environment, however, it may be much more difficult for the UAV to use images for autonomous flight purposes because the rain or snow may partially occlude objects of interest (e.g., buildings, trees, etc.) in the captured images. Furthermore, in the process of building a 3D model of the UAV's environment from a collection of images, rain or snow that is present in the environment will be included in such 3D models by virtue of rain and snow being real objects that are detectable in image data. Over time, this “noise” caused by the rain or snow is compounded in the 3D model of the environment, thereby degrading the accuracy of the 3D model. This, in turn, makes it difficult for the UAV to discern its true environment during flight.